In earlier times both Obama and other Democrats praised Paul Ryan

What a difference an election can make. In earlier times before Paul Ryan became the Republican vice-presidential candidate he was praised by some Democrats including Barack Obama.

Who else but Fox news would find videos with Democrats including Obama praising Paul Ryan the vice-presidential choice of Mitt Romney? Nevertheless factoids are factoids and the videos are not made up! The Obama video is here.
The video should be interpreted in context. Obama was speaking at a Republican retreat and it was at a time when he was stressing bipartisanship. Even so his speech is in sharp contrast to the negative rhetoric coming from Obama and the Democrats about Ryan at present. Now he is supposedly on the extreme right and that ultimate right-wing menace the Tea Party has now shown it has undue influence in the Republican Party.
The press now crows that there are clear choices. But both main parties represent primarily the most powerful interests helping to fund the two main parties when they are not lobbying for laws favorable to their cause. There is the liberal hero who will help the downtrodden and save the middle class Barack Obama and then there is the conservative hero who will have a smaller government and less regulation and get the economy moving again Mitt Romney. However, as Obama points out in his speech on the video he shares many of the ideas of Ryan and agrees that Ryan's ideas are serious. Although opposed to the voucher system proposed by Ryan he applauds his concern for reducing the costs in the U.S. medical care system and as with Ryan recognizes it as a core problem.
Even more praise is lavished on Ryan by Erkine Bowles in the featured video. Bowles is a senior Democrat. He was chief of staff under Bill Clinton and also co-chair of Obama's deficit-reduction committee. In a 2011 talk at the University of California, Bowles calls Ryan amazing. He goes on.
"I always thought I was okay with arithmetic. This guy can run circles around me, and he is honest, he is straightforward, he is sincere....And the budget he came forward with is just like Paul Ryan. It is a sensible, straightforward, honest, serious budget."Is this the same guy who wants to throw grandma off the cliff?
In March 29, 2012 in an interview Bowles said that the Ryan plan to buy private insurance should remain an option. What is not an option for Obama and the Democrats is a universal single-payer system as most advanced capitalist countries have in some form. He went on to say that Ryan's newer plan that allows people to keep traditional Medicare as an alternative should be considered. In 2010 in a PBS interview he said that:
"I wish we had more people like Paul who are thinkers and do their homework."
Ryan had worked together with Democratic Senator Ron Wyden to present an altered Medicare plan that added an option to the vouchers so that seniors could choose between government-subsidized private insurance and traditional government Medicare. This shows that Ryan is far from the picture of an uncompromising ideologue that the Democrats want the public to see in Ryan. Senator Wyden said about the joint plan:
"And much of what we're going to have to do with Medicare is to be sure that traditional Medicare with its purchasing power can be maintained, while at the same time we offer private sector choices, so that the two will strengthen each other. And in that sense, we recognize that much of the Medicare debate is not at all ideological."I think that rather than not being ideological the two parties share the same ideology meant to promote global capitalism. When it comes to selling the system what you need is product differentiation.
For that system to work you need at least two differentiated products. Having only two products, Democrats and Republicans, is probably the cheapest and most efficient system although many countries use a multiple product system. The media and party propaganda must seek to differentiate the two products. The public must see the system as providing genuine choice. Although as the videos show Democrats and Republicans share many positions this fact would go against the differentiation needed at election time.